German Published Patent Application No. 19 910 576 describes a parking lock mechanism for a countershaft transmission of a motor vehicle. The transmission shaft can be locked relative to a transmission housing by the parking lock mechanism. For this purpose, a sliding sleeve is arranged coaxially on the transmission shaft in a rotationally fixed connection. The sliding sleeve can be secured, engaged with a toothed ring supported in a rotationally fixed manner with respect to the transmission housing. The transmission shaft is mounted via a tapered roller bearing with respect to the transmission housing.
Furthermore, U.S. Pat. No. 5,651,435 describes a vehicle transmission according to a different generic definition having a reverse gear braking device with which a transmission shaft can be frictionally locked relative to a conical ring in a rotationally fixed connection to the transmission housing.
It is an object of the present invention to provide an inexpensive parking lock mechanism for a countershaft transmission.